[CINC] Article

[Ron Dreher]

Channel Islands alive with plants from another epoch Pacific Log Peter
Howorth 


 

April 20, 2008 12:00 AM

PETER HOWORTH PHOTOS

The Channel Islands are home to many species of plants that, like the
recently discussed island night lizard, are representatives of long-past
ages. Above, giant coreopsis plants grace Prisoner's Harbor on Santa Cruz
Island. At right, a monkey flower is pictured on Santa Cruz Island, one of
only three places the species exists. At far right, a live forever, a
succulent with thick pointed leaves, is shown on San Nicolas Island.

Last week's Pacific Log dealt mainly with fossils on the Channel Islands.
But a number of plants still living on the islands represent ages long gone,
while others reveal how plants can evolve into forms found nowhere else in
the world.

Santa Cruz Island ironwood is a case in point. This lovely tree graces steep
slopes along the island's north side, where it grows in cool, shaded groves.
Like the island night lizard (discussed recently in this column), the
ironwood is a relict species, meaning a leftover from another epoch -- this
species was widespread on the mainland 6 million to 19 million years ago.
Now it is only found on Santa Cruz, Santa Rosa and San Clemente islands,
thus it is considered an island endemic.

Actually, this is not entirely true; Santa Cruz Island ironwoods, like a
number of island plant species, have found their way to gardens on the
mainland. Santa Catalina Island also has its own ironwood species, although
it only grows naturally on its namesake island.

Another interesting tree is found in a small area along the east end of
Santa Rosa Island. This is the Torrey pine, most often associated with the
Torrey pines near La Jolla. That Torrey pines are found on Santa Rosa Island
is no accident; while the huge section of the earth's crust known as the
oceanic plate dives under the continental plate, it has also been slowly
moving northward. Instead of a land bridge near Point Mugu, what are now the
northern Channel Islands were once connected to the mainland much farther
south.

The Santa Cruz Island pine has been the subject of controversy among
taxonomists for some time. Some researchers say it should be considered a
separate species, while others see the Santa Cruz Island pine and the Bishop
pine as one and the same. Some botanists have noted intermediate forms
between the two. Suffice it to say that pines grow near China Harbor, from
Pelican Bay to Fry's Harbor, and inland from Christy Ranch, on the west end
of the island.


 

Various trees are not the only unusual plants found on the islands.
Live-forevers, succulents with thick pointed leaves, grow on many of the
islands. Some are unique to one island, while others are found on two or
more islands and sometimes on the mainland as well.

Santa Cruz Island has its own live-forever, along with another species that
is found both on Santa Cruz and Santa Rosa islands.

One species of monkey flower is found only along cool canyons and slopes of
Anacapa, Santa Cruz and Santa Rosa islands. Island endemic buckwheats
include the Santa Cruz Island buckwheat, which is also found on Anacapa and
Santa Rosa islands and St. Catherine's lace, endemic to Santa Catalina
Island and often planted along coastal highways.

One of the most spectacular plants looks most of the year as if it died a
terrible death. This is the sea dahlia, sometimes simply called the giant
coreopsis. Like many plants, it is found not only on the islands but also on
the mainland. A small colony exists just west of Gaviota. North of Point
Conception it is more widespread. It is also found along Highway 1 south of
Point Mugu.

Except in early spring, the dull brown coreopsis trunks, sometimes standing
over five feet tall, are crowned only with dead foliage. But the plants are
very much alive, and come spring, carrot-like leaves appear, along with
beautiful yellow flowers. Parts of the Channel Islands become so bright with
the flowers of this plant that the colors can be seen from the mainland on a
clear day.

Arguably the best place to see the plants of the Channel Islands is right in
our own backyard, at the Santa Barbara Botanic Garden. An entire section is
devoted to plants found on the islands of California and Mexico, plus island
plants can be found in other parts of the garden.

Peter Howorth is director of the Santa Barbara Marine Mammal Center.

 

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